Welding strip and centrifugal casting



Aug. 29, 1939. w. D. SARGENT 2,171,405 WELDING STRIP AND CENTRIFUGAL CASTING Filed Feb. 10, 1952 2 Sheets-Sheet 1 w &

9, 1939. w. D. SARGENT 2,171,405

WELDING STRIP AND CENTRIFUGAL CASTING Filed Feb. 10, 1932' 2 Sheets-Sheet 2 Patented Aug. 29, 1939 PATENT OFFICE WELDING STRIP AND CENTRIFUGAL CASTING William D. Sargent, New York, N. Y., assignor to Durai'er (Inc Dover, Del., a corporation of Delaware Application February 10, 1932, Serial No. 592,003

3 Claims.

The present invention relates to castings and casting operationsv and embodies, more specifically, an improved centrifugal casting and casting method wherein a steel welding strip is provided in the casting to facilitate its mounting in a desired position. In the art of centrifugal casting, for example, in the casting of brake drums and the like for motor vehicles, it is frequently desirable to provide a predetermined article of centrifugally cast metal and secure the same to a supporting structure in a suitable fashion after the casting operation has been completed. While the present invention will be described in connection with brake drums and liners for motor vehicles, it

.. will be apparent that it is applicable to any centrifugal casting or method wherein articles are similarly cast. To strengthen cast articles of this character it has been found desirable to provide a reinforcing strip by means of which the article is secured to a supporting structure and the present invention has, for an object, the provision of a cast article wherein aminforcing strip is included to facilitate securing of the cast article to a supporting structure.

- A further object of the invention is to provide a device of the above character, wherein a securing strip is united with the cast metal, the metal of the strip being of a predetermined character to facilitate securing of the cast article to a desired structure.

A further object of the invention is to provide a device of the above character wherein a supporting or reinforcing strip is included in the article, the metal of the article being cast about the strip to engage therewith and provide a unitary casting with predetermined properties.

A further object of the invention is to'provide a casting method wherein metal is centrifugally cast about a suitable reinforcing strip.

A further object of the invention is to pro;

vide a method of the above character wherein metal is cast centrifugally into a mold, the metal coming in contact with a supporting and reinforcing strip about which the metal is to be I cast, such contact taking place prior to engagement of the metal with the mold.

A further object of the invention is to provide a method -of casting centrifugally anarticle in which a reinforcing element is provided, the

method being such as to effect fusion of the element during casting Without preheating the element prior to thecasting operation.

Further objects, not specifically enumerated above, will be apparentas the invention is described in greater detail in connection with the accompanying drawings, wherein:

Figure 1 is a segmental view in section, showing'a mold provided with a welding ring and adapted for molding operations in accordance 5 with the present invention.

Figure 2 is a segmental view in section, showing an article cast with a welding or mounting ring in accordance with the present invention and secured to a suitable supporting structure. 10

Figure 3 is a view similar to Figure 1, showing a modified supporting ring structure.

Figure 4 is a view in elevation showing a segment of a casting formed in accordance with the present invention with a welding ring of the 15 above character shown in Figure 3.

Figure 5 is a view in section, similar to Figure 2, showing the welding ring of Figure 3 in a casting and preparatory to being secured to a supporting structure. 20

Figure 6 is a view similar to Figures 1 and 3 showing a further modified welding ring construction.

"Figure '7 is a view in section, similar to Figure 2, showing a casting. formed with a welding 25 ring and adapted to be machined to the form indicated by the dot and dash line,

Figure 8 is a view similar to Figure 7 showing the casting after effecting the machining operation and mounting the same upon a supporting 30 structure. Y

Figure 9 is a view similar to Figure 1, showing a,modified form of welding ring.

Figure 10 is a detail view showing the casting formed as indicated in Figure 9 after being 35 mounted upon a supporting'structure.

Figure 11 is a view similar to Figure 1, showing a modified form of welding ring structure.

Figure 12 is a'plan view of a reinforcing structure for a casting formed in accordance with the 40 present invention.

Figure 13 is a view similar to Figure 12, showing a further form of reinforcing element.

Figure 14 is a view similar to Figures 12 and 13, showing a further modified form of .)reinforcing. 45

Figure 15 is a view in section through a casting in which a reinforcing element has been embodied, similar to the constructon illustrated in Figure 12,

Figure 16 is a view similar to Figure 15, show- 50 ing a slightly modified reinforcing structure.

In connection with centrifugal castings and casting operations it is frequently desirable to provide an effective means to facilitate the mounting of the casting upon a supporting struc- 55 20 ring l4, the dove-tails l5 effectively engaging ture. In the case of brake drums and the like for motor vehicles, to lend the structure more readily to the effective mounting thereof upon a wheel, a welding or supporting ring is inserted within the mold adjacent the bottom thereof. Inthe form of ring shown in Figure 1, the mold I is adapted to bemounted upon a rotatable base ll within which a casting element [2 is formed having an annular trough [3. Within the mold and adjacent the bottom thereof, a welding ring I4 is inserted. This ring may be formed with dove-tailed extensions i5 in order that the metal may be cast effectively about the ring and cause the same to be united integrally with-the casting. The lower extremity N3 of the ring is preferably protected by a portion of the mold in order that it may be projected from the casting after the casting operation has been completed. As seen in Figure 2, the casting l1, produced by the mold I0, is formed integrally with the welding the casting and the extension 18 serving as an effective means for securing the casting to a mounting member [8 by welding the same at l9.

In the form of ring shown in Figure 3, extensions 20 are provided on the ring and preferably bent inwardly to be imbedded within the metal of the casting. Projecting tabs 2! are formed upon the opposite side of the ring and project downwardly from the casting as shown in Figure 4. Figure 5 illustrates the manner in which the projections 2| may be bent to facilitate the securing of the casting to a suitable mounting structure.

In the form of construction illustrated in Figure 6, a ring 22 is provided with a plurality of spaced apertures 23 and a peripheral inwardly extending flange 24. The metal of the casting flows into the apertures 23 and thus efiectively unites itself with the welding ring construction.

In the form of the invention illustrated in Figures 7 and 8, it is proposed to cast the article with a ring and subsequently machine the casting to a predetermined size for fitting over a supporting structure, To this end, Figure '7 illustrates a casting 25 with a portion 26 (indicated by the dot and dash line of Figure 7) which is adapted to be machined from the casting, the portion 26 including an annular portion 21 which is formed adjacent a welding ring 28 upon which the metal is cast, After the machining operation, the casting takes the form illustrated in Figure 8 and is thus adapted to be mounted upon a supporting disc or structure 29 and welded thereto as indicated at 30.

In the form of the invention illustrated in Figure 9, the welding ring 31 is provided with a curved inner surface in order that the metal may be cast about such surface to cause the imbedding of the ring in the casting. In Figure 10, the ring 3| is shown as secured to a supporting disc 32 by means of a bolt 33 and welding 3|. Obviously, either of these securing means may be utilized to the exclusion of the other although of such structure in combination with a welding' ring. Figure 12 illustrates one form of such reinforcing structure, this figure illustrating a strip of metal 31 having an expanded portion 38 which is formed into a mesh which preferably increases in size as the expanded metal is more remote from the strip 31. The expanded portion is imbedded in the casting as illustrated in Figures 15 and 16, the form shown in Figure 15 illustrating expanded metal whereof the portions lie in planes at angles to the plane of the strip 31, while the form shown in Figure 16 illustrates the portions of metal forming the mesh after having been flattened to lie in substantially the same plane as the strip 31, I

The reinforcing section of expanded metal 38 and solid strip 31 is placed into the mold with the solid strip adjacent the bottom thereof whereby the casting of the metal centrifugally into the mold from the pouring trough engages first the solid strip 31 and finer mesh adjacent thereto.

This comparatively great quantity of metal ad jacent the bottom of the mold thus protects the adjacent mold surfaces from the highly heated metal. Of course, it will be seen that the border 31 of solid stock may be omitted-if desired.

-In the form of the reinforcing element shown in Figure 13, solid borders 3!! and 40 are formed upon each side of the expanded metal stock, the mesh of the expanded portion increasing in size to the median section of the element from each border.

Where the casting is to be reinforced principally at the upper or outer portion thereof, as'

is sometimes desirable in brake drums for motor vehicles, the expanded metal stock of Figure 12 may be inverted and placed in the mold in the position illustrated in Figure 14, the solid border 31 being at the top of the mold instead of at the bottom as in the form illustrated in Figures 12, 15 and 16.

To facilitate the fusion and binding of the expanded metal stock with the metal of the casting, the stock may be coated within, aluminium, zinc or other suitable metal and various modiflcations in the form and structure of the reinforcing element may be made without departing from the scope of this invention.

From the foregoing, it will be seen that the hot metal which is precipitated from the trough by centrifugal action first strikesthe steel welding ring insert before it reaches the upper part of the mold and thus practically all of the hot metal comes in contact with the insert. This not only results in preheating of the ring and the preparation thereof forfusion but it also protects the bottom of the mold where the hot metal first strikes and thus enables the mold to be used for a longer period of time than otherwise possible. It should be noted that the foregoing operation effects fusion of the ring with the.

metal of the casting, without preheating of the ring prior to the casting operation. The ring is simply inserted into the mold at its normal temperature and the casting operation is carried out as above described, the casting of the molten metal upon the strip centrifugally serving to fuse it.

If desired, the fusion of the strip with the cast metal may be facilitated by coating the surface of the strip with zinc or aluminium or other substances which, in combustion, raise the temperature of the surface with which itis in contact. A further distinctive feature of the, invention is that the welding rings or strips may be slightly more" tapered than is necessary to conform to the taper in the mold, thus imparting a 'line contact or hearing on the side surface of the mold between the ring or strip and the mold. It also has a line bearing against the base ring of the mold and the positioning of the ring within the mold is thus facilitated. As expansion of the ring takes place under impact of the hot metal which is cast against it, the ring or strip seats itself fully against the side of the mold.

From the foregoing, it will be seen that an improved casting is provided which is formed with a supporting and welding ring to facilitate the mounting of the casting upon a desired supporting structure this supporting or welding ring additionally serving as a means for protecting the mold. The method of casting is such as to unite the welding ring effectively with the cast metal and cause the same to become an integral part thereof. The improved machine provided by the present invention is of such character as to remove or elevate the casting effectively from the lower mold section and thus facilitate the stripping and removal of the casting from the mold. 4

While the invention has been described with specific reference to the accompanying drawings, it is not to be limited, save as defined in the appended claims.

This application is a continuation in part of application No. 573,353 applied for November 6,

1931, and issued May 28, 1935 as Patent No. 2,002,962.

I claim as my invention: a

1. A centrifugal casting comprising an ann lar body of centrifugally cast-.metal having an annular mesh reinforcing metallic element fused therewith during casting, said element having an annular solid portion lying adjacent the outer surface of the casting, the size of the mesh of the element varying progressively from the median plane thereof.

2. A centrifugal casting comprising an annular body of centrifugally cast metal having an annular mesh reinforcing metallic element fused therewith during casting, said element having an annular solid portion lying adjacent the outer surface of the casting, the size of the mesh of the element increasing progressively from the solid portion.

3. A centrifugal casting comprising an annular body of centrifugally cast metal having an annular mesh reinforcing metallic element fused therewith during casting, said element having annular solid portions at either end lying adjacent the outer surface of the casting and the mesh of the element increasing progressively in size from the solid portions to the median plane thereof.

WILLIAM D. SARGENT. 

